The present invention relates, in general, to electronics and, more particularly, to methods for forming electronic devices such as semiconductor dies.
In the past, the semiconductor industry utilized various methods and equipment to singulate individual semiconductor die from a semiconductor wafer on which the die was manufactured. Typically, a technique called scribing or dicing was used to either partially or fully cut through the wafer with a diamond cutting wheel along scribe grids or singulation lines that were formed on the wafer between the individual die. To allow for the alignment and the width of the dicing wheel each scribe grid usually had a large width, generally about one hundred fifty (150) microns, which consumed a large portion of the semiconductor wafer. Additionally, the time required to scribe each singulation line on the semiconductor wafer could take over one hour or more. This time reduced the throughput and manufacturing capacity of a production facility.
Other methods, which have included thermal laser separation (TLS), laser ablation dicing, and plasma dicing, have been explored as alternatives to scribing. Plasma dicing is a promising process compared to scribing and other alternative processes because it supports narrower scribe lines, has increased throughput, and can singulate die in varied and flexible patterns. However, plasma dicing has had manufacturing implementation challenges. Such challenges have included non-compatibility with wafer backside layers, such as back metal layers, because the etch process has been unable to effectively remove or separate the backside layers from the singulation lines. Removing or separating the backside layers from the scribe lines is necessary to facilitate subsequent processing, such as pick-and-place and assembly processes.
Accordingly, it is desirable to have a method of singulating die from a semiconductor wafer that removes or separates the backside layers from within the singulation lines. It would be beneficial for the method to be cost effective and to minimize any damage to or contamination of the separated die.